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EP1634706B1 - Liquid jet device and liquid jet method - Google Patents

Liquid jet device and liquid jet method Download PDF

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Publication number
EP1634706B1
EP1634706B1 EP04746236A EP04746236A EP1634706B1 EP 1634706 B1 EP1634706 B1 EP 1634706B1 EP 04746236 A EP04746236 A EP 04746236A EP 04746236 A EP04746236 A EP 04746236A EP 1634706 B1 EP1634706 B1 EP 1634706B1
Authority
EP
European Patent Office
Prior art keywords
liquid
ejection
ejecting
head
droplets
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP04746236A
Other languages
German (de)
English (en)
French (fr)
Other versions
EP1634706A4 (en
EP1634706A1 (en
Inventor
Soichi Kuwahara
Kazuyasu Takenaka
Iwao Ushinohama
Yuichiro Ikemoto
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sony Corp
Original Assignee
Sony Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Sony Corp filed Critical Sony Corp
Publication of EP1634706A1 publication Critical patent/EP1634706A1/en
Publication of EP1634706A4 publication Critical patent/EP1634706A4/en
Application granted granted Critical
Publication of EP1634706B1 publication Critical patent/EP1634706B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
    • B41J2/01—Ink jet
    • B41J2/015—Ink jet characterised by the jet generation process
    • B41J2/04—Ink jet characterised by the jet generation process generating single droplets or particles on demand
    • B41J2/045—Ink jet characterised by the jet generation process generating single droplets or particles on demand by pressure, e.g. electromechanical transducers
    • B41J2/04501—Control methods or devices therefor, e.g. driver circuits, control circuits
    • B41J2/0458—Control methods or devices therefor, e.g. driver circuits, control circuits controlling heads based on heating elements forming bubbles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
    • B41J2/01—Ink jet
    • B41J2/015—Ink jet characterised by the jet generation process
    • B41J2/04—Ink jet characterised by the jet generation process generating single droplets or particles on demand
    • B41J2/045—Ink jet characterised by the jet generation process generating single droplets or particles on demand by pressure, e.g. electromechanical transducers
    • B41J2/05—Ink jet characterised by the jet generation process generating single droplets or particles on demand by pressure, e.g. electromechanical transducers produced by the application of heat
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
    • B41J2/01—Ink jet
    • B41J2/015—Ink jet characterised by the jet generation process
    • B41J2/04—Ink jet characterised by the jet generation process generating single droplets or particles on demand
    • B41J2/045—Ink jet characterised by the jet generation process generating single droplets or particles on demand by pressure, e.g. electromechanical transducers
    • B41J2/04501—Control methods or devices therefor, e.g. driver circuits, control circuits
    • B41J2/04505—Control methods or devices therefor, e.g. driver circuits, control circuits aiming at correcting alignment
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
    • B41J2/01—Ink jet
    • B41J2/015—Ink jet characterised by the jet generation process
    • B41J2/04—Ink jet characterised by the jet generation process generating single droplets or particles on demand
    • B41J2/045—Ink jet characterised by the jet generation process generating single droplets or particles on demand by pressure, e.g. electromechanical transducers
    • B41J2/04501—Control methods or devices therefor, e.g. driver circuits, control circuits
    • B41J2/04526—Control methods or devices therefor, e.g. driver circuits, control circuits controlling trajectory
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
    • B41J2/01—Ink jet
    • B41J2/015—Ink jet characterised by the jet generation process
    • B41J2/04—Ink jet characterised by the jet generation process generating single droplets or particles on demand
    • B41J2/045—Ink jet characterised by the jet generation process generating single droplets or particles on demand by pressure, e.g. electromechanical transducers
    • B41J2/04501—Control methods or devices therefor, e.g. driver circuits, control circuits
    • B41J2/04533—Control methods or devices therefor, e.g. driver circuits, control circuits controlling a head having several actuators per chamber
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
    • B41J2/01—Ink jet
    • B41J2/015—Ink jet characterised by the jet generation process
    • B41J2/04—Ink jet characterised by the jet generation process generating single droplets or particles on demand
    • B41J2/045—Ink jet characterised by the jet generation process generating single droplets or particles on demand by pressure, e.g. electromechanical transducers
    • B41J2/04501—Control methods or devices therefor, e.g. driver circuits, control circuits
    • B41J2/04541—Specific driving circuit
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
    • B41J2/01—Ink jet
    • B41J2/015—Ink jet characterised by the jet generation process
    • B41J2/04—Ink jet characterised by the jet generation process generating single droplets or particles on demand
    • B41J2/045—Ink jet characterised by the jet generation process generating single droplets or particles on demand by pressure, e.g. electromechanical transducers
    • B41J2/04501—Control methods or devices therefor, e.g. driver circuits, control circuits
    • B41J2/04578—Control methods or devices therefor, e.g. driver circuits, control circuits controlling heads based on electrostatically-actuated membranes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
    • B41J2/01—Ink jet
    • B41J2/015—Ink jet characterised by the jet generation process
    • B41J2/04—Ink jet characterised by the jet generation process generating single droplets or particles on demand
    • B41J2/045—Ink jet characterised by the jet generation process generating single droplets or particles on demand by pressure, e.g. electromechanical transducers
    • B41J2/04501—Control methods or devices therefor, e.g. driver circuits, control circuits
    • B41J2/04581—Control methods or devices therefor, e.g. driver circuits, control circuits controlling heads based on piezoelectric elements
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
    • B41J2/01—Ink jet
    • B41J2/07—Ink jet characterised by jet control
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
    • B41J2/01—Ink jet
    • B41J2/135—Nozzles
    • B41J2/14—Structure thereof only for on-demand ink jet heads
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
    • B41J2/01—Ink jet
    • B41J2/135—Nozzles
    • B41J2/14—Structure thereof only for on-demand ink jet heads
    • B41J2/14016—Structure of bubble jet print heads
    • B41J2/14032—Structure of the pressure chamber
    • B41J2/1404—Geometrical characteristics
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
    • B41J2/01—Ink jet
    • B41J2/135—Nozzles
    • B41J2/14—Structure thereof only for on-demand ink jet heads
    • B41J2/14016—Structure of bubble jet print heads
    • B41J2/14032—Structure of the pressure chamber
    • B41J2/14056—Plural heating elements per ink chamber
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
    • B41J2/01—Ink jet
    • B41J2/135—Nozzles
    • B41J2/14—Structure thereof only for on-demand ink jet heads
    • B41J2/14016—Structure of bubble jet print heads
    • B41J2/14088—Structure of heating means
    • B41J2/14112—Resistive element
    • B41J2/1412—Shape
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
    • B41J2/01—Ink jet
    • B41J2/135—Nozzles
    • B41J2/145—Arrangement thereof
    • B41J2/155—Arrangement thereof for line printing
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J25/00—Actions or mechanisms not otherwise provided for
    • B41J25/001—Mechanisms for bodily moving print heads or carriages parallel to the paper surface
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J29/00—Details of, or accessories for, typewriters or selective printing mechanisms not otherwise provided for
    • B41J29/38—Drives, motors, controls or automatic cut-off devices for the entire printing mechanism
    • B41J29/393—Devices for controlling or analysing the entire machine ; Controlling or analysing mechanical parameters involving printing of test patterns
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2202/00—Embodiments of or processes related to ink-jet or thermal heads
    • B41J2202/01—Embodiments of or processes related to ink-jet heads
    • B41J2202/20—Modules
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2202/00—Embodiments of or processes related to ink-jet or thermal heads
    • B41J2202/01—Embodiments of or processes related to ink-jet heads
    • B41J2202/21—Line printing

Definitions

  • the present invention relates to a liquid ejection apparatus having a line head arranged by juxtaposing a plurality of liquid ejection parts of unit heads so as to connect the unit head to the adjacent unit head, each unit head having at least part of the liquid ejection part for ejecting ink droplets from a nozzle, and a liquid ejection method using the line head having a plurality of the unit heads by juxtaposing a plurality of the unit heads so as to connect the unit head to the adjacent unit head, each unit head having at least part of the liquid ejection part for ejecting ink droplets from the nozzle.
  • the present invention relates to a technique in that the ejecting direction of ink droplets is individually set for each unit head so that every unit heads constituting the line head can eject ink droplets in directions appropriately for each unit head.
  • An ink-jet printer has been known as an example of the liquid-ejecting apparatus.
  • the ink-jet printer there have been known a serial system, in which while ink droplets ejected from a head moving in the lateral direction of a recording medium are landed on the recording medium moving, the recording medium is moved in a conveying direction, and a line system having a line head arranged along the entire width of the recording medium so as to move only the recording medium in a direction perpendicular to the lateral direction of the recording medium while ink droplets ejected from the line head are landed on the recording medium.
  • the line head has been known to have a structure having a plurality small head chips (referred to as a unit head below) juxtaposed so as to connect the unit heads together at their ends so that liquid ejection parts, each part being composed of each unit head, are arranged along the entire width of photographic paper.
  • a unit head a structure having a plurality small head chips (referred to as a unit head below) juxtaposed so as to connect the unit heads together at their ends so that liquid ejection parts, each part being composed of each unit head, are arranged along the entire width of photographic paper.
  • each ejection part is provided with at least two energy generating elements so that ink droplets are ejected from the ejection parts in a plurality of directions by controlling the two energy generating elements while the ink-ejecting directions are varied at random.
  • the line system may be incorporated.
  • JP 2002-240287 discloses varying the ejecting direction of each nozzle hesters independently.
  • the dispersion can be made in inconspicuous states.
  • Fig. 29 three heads 1 of Nth, (N+1)th, and (N-1)th head 1, are only shown; however, a further large number of the heads 1 are juxtaposed in the lateral direction of the drawing in practice.
  • liquid ejection parts each including a nozzle and having an ejection function of ink droplets
  • P about 42.3 ⁇ m at a resolution of 600 DPI, for example
  • the heads 1 are juxtaposed so as to have also a pitch P of joints between the heads 1, the joint between the liquid ejection part positioned at the right most of the Nth head 1 and the liquid ejection part positioned at the left most of the (N+1) th head 1, for example.
  • the Nth head 1 is displaced to a position closer to the (N-1)th head 1, the Nth head 1 is arranged at a position further than the (N+1)th head 1.
  • ink droplets ejected from the liquid ejection part positioned at the right most in the drawing of the (N-1)th head 1 excessively approach ink droplets ejected from the liquid ejection part positioned at the left most in the drawing of the Nth head 1, so that a conspicuous stripe A is unfavorably produced in the boundary between the heads 1 in the conveying direction of photographic paper P (vertical direction in the drawing).
  • ink droplets ejected from the liquid ejection part positioned at the right most in the drawing of the Nth head 1 are excessively separated from ink droplets ejected from the liquid ejection part positioned at the left most in the drawing of the (N+1)th head 1, so that a conspicuous white stripe A is unfavorably produced.
  • the (N-1)th, Nth, and (N+1)th head 1 are arranged at predetermined intervals, respectively, there may be a head 1 with an ejecting direction different from those of other heads 1, such that the ejecting direction of ink droplets ejected from the liquid ejection part of the Nth head 1 is inclined to the (N-1)th head 1, for example.
  • ejection characteristics such as ejecting directions, vary for every the heads 1 due to errors in manufacturing.
  • stripe unevenness can be alleviated by changing the ink ejecting direction at random.
  • the range of the changes has a predetermined limit. That is, if the ejecting direction is changed at random so as to exceed the predetermined limit, exact pixels cannot be formed.
  • the line head is formed so as to connect the heads 1 together, the ejection characteristics may be displaced so as to exceed a limit allowable for alleviating stripe unevenness by changing the ejecting direction. In such a case, the stripe unevenness may not be made inconspicuous by only changing the ejecting direction at random.
  • the present invention solves the above-object by the liquid ejection apparatus and the liquid ejection methods as defined in the independent claims. Further embodiments are defined in the dependent claims.
  • the liquid ejection apparatus includes principal control means for controlling each of the liquid ejection part to eject liquid droplets from the nozzle; auxiliary control means for controlling liquid droplets to be ejected in at least one direction different from the ejection direction controlled by the principal control means in the arranging direction of the liquid ejection parts; and auxiliary control execution determining means for individually setting whether the auxiliary control means is executed for each of the unit head.
  • auxiliary control means it is determined whether the auxiliary control means is executed for each unit head by toe auxiliary control execution determining means.
  • toe auxiliary control execution determining means it is determined whether the auxiliary control means is executed for each unit head.
  • the liquid ejection apparatus includes ejection direction changing means for enabling the ejection direction of liquid droplets ejected from the nozzle of each of the liquid ejection part to change in at least two different directions in the arranging direction of the liquid ejection parts; and reference-direction setting means for individually setting one reference principal direction for each of the unit head among a plurality of ejection directions of liquid droplets established by the ejection direction changing means.
  • the ejection direction changing means is provided for each unit head, so that liquid droplets can be ejected in at least two different directions in the arranging direction of the liquid ejection parts.
  • the liquid ejection apparatus includes ejection direction changing means for enabling the ejection direction of liquid droplets ejected from the nozzle of each of the liquid ejection part to change in at least two different directions in the arranging direction of the liquid ejection parts; and ejecting-angle setting means for individually setting liquid droplets established by the ejection direction changing means for each of the unit head.
  • the ejection direction changing means is provided for each liquid ejection part of the unit head, so that ink droplets can be ejected in at least two different directions in the arranging direction of liquid ejection parts.
  • one pixel region On one pixel region, a predetermined number of ink droplets (zero, one, or a plurality of droplets) are landed so as to form a pixel without a dot (one-step gradation), a pixel with one dot (two-step gradation), and a pixel with a plurality of dots (three-step or more gradation). That is, one pixel region corresponds to zero, one, or a plurality of dots. Thus, a large number of these pixels are arranged on a recording medium so as to form images.
  • the dots corresponding to the pixel are not completely contained within the corresponding pixel region, and some dots may lie off the pixel region.
  • Fig. 1 is an exploded perspective view of a unit head 11 (simply referred to a head 11 below) of an ink-jet printer (simply referred to a printer below) incorporated in a liquid ejection apparatus according to the present invention.
  • the head 11 shown in Fig. 1 is composed of a plurality of juxtaposed liquid ejection parts.
  • the liquid ejection part includes an ink chamber 12 for containing liquid to be ejected, a heating resistor 13 (equivalent to bubble-generating means or a heating element according to the present invention) arranged within the ink chamber 12 for generating bubbles in the liquid contained in the ink chamber 12 by supplying energy, and a nozzle sheet 17 (equivalent to a nozzle-forming member according to the present invention) having nozzles 18 formed thereon for ejecting liquid operatively associated with the bubble generation by the heating resistor 13.
  • a heating resistor 13 equivalent to bubble-generating means or a heating element according to the present invention
  • the nozzle sheet 17 is bonded on a barrier layer 16, and the nozzle sheet 17 is shown by being exploded in the drawing.
  • a substrate member 14 includes a semiconductor substrate 15 made of silicon, etc. and the heating resistors 13 deposited on one surface of the semiconductor substrate 15.
  • the heating resistor 13 is electrically connected to an external circuit via a conduction part (not shown) formed on the semiconductor substrate 15.
  • the nozzle sheet 17 having a plurality of the nozzles 18 is made by an electrocasting technique with nickel, and is bonded on the barrier layer 16 so that positions of the nozzles 18 agree with those of the heating resistors 13, i.e., the nozzles 18 oppose the heating resistors 13, respectively.
  • the ink chamber 12 is constituted of the substrate member 14, the barrier layer 16, and the nozzle sheet 17 so as to surround the heating resistor 13. That is, in the drawing, the substrate member 14 forms the bottom wall of the ink chamber 12; the barrier layer 16 forms side walls of the ink chamber 12; and the nozzle sheet 17 forms the top wall of the ink chamber 12.
  • the ink chamber 12 has an opening region in front right of Fig. 1 , and the opening region is communicated with an ink flow path (not shown).
  • the above-mentioned one head 11 generally includes the ink chambers 12 in units of several tens to several hundreds and the heating resistors 13 arranged within each of the ink chambers 12.
  • the heating resistor 13 can be respectively selected so as to eject ink contained in the ink chamber 12 corresponding to the heating resistor 13 from the nozzle 18 opposing the ink chamber 12.
  • the ink chamber 12 is filled with ink from an ink tank (not shown) connected to the head 11. Then, by applying a pulse electric current to the heating resistor 13 for a short time, such as 1 to 3 ⁇ s, the heating resistor 13 is rapidly heated, resulting in generating gas-phase bubbles in ink contacting the heating resistor 13 so as to push aside some volume of ink (ink is evaporated) by the expansion of the ink bubbles. Thereby, ink contacting the nozzle 18 with the same volume as that of pushed ink is ejected from the nozzle 18 as ink droplets, and is landed on photographic paper so as to form dots (pixels) thereon.
  • a pulse electric current to the heating resistor 13 for a short time, such as 1 to 3 ⁇ s
  • the heating resistor 13 is rapidly heated, resulting in generating gas-phase bubbles in ink contacting the heating resistor 13 so as to push aside some volume of ink (ink is evaporated) by the expansion of the ink bubbles.
  • the line head is formed to have a plurality of the liquid ejection parts of the heads 11 arranged by placing a plurality of the heads 11 in an arranging direction of the liquid ejection parts (arranging direction of the nozzles 18 or the width direction of a recording medium) so as to connect the heads 11 together.
  • Fig. 2 is a plan view showing an embodiment of a line head 10. In Fig. 2 , the four heads 11 ((N-1), (N), (N+1), and (N+2)) are shown; however, a further large number of the heads 11 are arranged so as to connect them together.
  • a plurality of parts of the heads 11 other than the nozzle sheet 17 (head chips) shown in Fig. 1 are first juxtaposed.
  • the line head 10 with one color is shown; a plurality of the line heads 10 may be provided so as to supply different color ink for each of the line heads 10 for forming a color line head.
  • the heads 11 adjacent to each other are arranged in one side and the other side, respectively across an ink flow path
  • the heads 11 on the one side oppose the heads 11 on the other side, i.e., the heads 11 are arranged so that the nozzles 18 oppose each other (a so-called staggered arrangement). That is, in Fig. 2 , a portion sandwiched by a line connecting external peripheries, adjacent to the nozzles 18, of the (N-1)th head 11 and the (N+1)th head 11 together and a line connecting external peripheries, adjacent to the nozzles 18, of the Nth head 11 and the (N+2)th head 11 together is the ink flow path of this line head 10.
  • the heads 11 are arranged so that the pitch between the nozzles 18 at ends of the heads 11 adjacent to each other, i.e., in detailed A portion of Fig. 2 , the space between the nozzle 18 at the right most of the Nth head 11 and the nozzle 18 at the left most of the (N+1)th head 11, is identical to the space between the nozzles 18 of the head 11.
  • each head 11 may also be arranged linearly (as straight as a line). That is, in Fig. 2 , the Nth and the (N+2)th head 11 may also be arranged identically to the (N-1)th and the (N+1)th head 11 in their directions.
  • the liquid ejection parts of each head 11 are arranged substantially in parallel with the juxtaposing direction of the heads 11; alternatively, the liquid ejection parts of each head 11 may be arranged in a line slanting to the right in Fig. 2 .
  • the liquid ejection parts of the head 11 are divided into a plurality of groups, the liquid ejection parts belonging to each group may be arranged in a line slanting to the right in Fig. 2 .
  • the head 11 also includes ejecting-direction changing means or principal control means and auxiliary control means.
  • the ejecting-direction changing means can change the ejecting direction of ink droplets ejected from the nozzle 18 of the liquid ejection part in at least two different directions of arranging directions of the liquid ejection parts.
  • the ejecting-direction changing means includes the principal control means for controlling each of the liquid ejection parts to eject ink droplets from the nozzle 18 and the auxiliary control means for controlling ink droplets to eject in at least one direction different from the ejecting direction of the ink droplets by the principal control means of the arranging direction of the liquid ejection parts.
  • the ejecting-direction changing means (the principal control means and the auxiliary control means) is constructed as follows.
  • Fig. 3 includes a plan view and a sectional side view showing the arrangement of the heating resistors 13 of the head 11 in detail.
  • the plan view of Fig. 3 additionally shows the position of the nozzle 18 with chain lines.
  • the two divided heating resistors 13 are juxtaposed. Moreover, the arranging direction of the two divided heating resistors 13 is the arranging direction of the liquid ejection parts.
  • the resistance value is doubled.
  • the heating elements 13 with doubled resistance are connected in series, resulting in quadrupling the resistance value.
  • the heating element 13 In order to boil ink contained in the ink chamber 12, it is required to heat the heating element 13 by applying predetermined electric power to the heating element 13 because the ink is ejected by the energy during the boiling. When the resistance is small, the current must be increased; however, by increasing the resistance value of the heating element 13, the ink can be boiled with smaller current.
  • a transistor for passing the current can also be reduced in size, resulting in space-saving.
  • Reduction in thickness of the heating element 13 increases the resistance value; however, in view of the material selected for the heating element 13 and the strength (durability) thereof, the reduced thickness of the heating element 13 has a predetermined limit. Accordingly, without reducing the thickness, the resistance value is increased by dividing the heating element 13.
  • ink is not boiled on the two heating elements 13 simultaneously, so that ink droplets are ejected away the axial direction of the nozzle 18 (deflected). Thereby, the ink droplets are landed at a position shifted off the landing position when ink droplets are ejected without deflection.
  • Figs. 4A and 4B are graphs showing the relationship between the time difference in ink-bubble generation by the divided heating resistors 13 according to the embodiment and the ejecting angle of ink droplets.
  • the values in the graphs are results from computer simulations.
  • an X-direction (the direction shown by ⁇ x plotted on an ordinate, note: not the abscissa of the graphs) is the arranging direction of the nozzles 18 (juxtaposing direction of the heating resistors 13), and a Y-direction (the direction shown by ⁇ y plotted on the ordinate, note: not the ordinate of the graphs) is the direction perpendicular to the X-direction (conveying direction of photographic paper).
  • ⁇ x and ⁇ y are shown as shifted angles when they are zero when without deflection:
  • Fig. 4C shows measured data, in which half of the current difference between the two pieces of the divided heating element 13 as the bubble-generating time difference is plotted on an abscissa as a deflection current while a deflection at a landing position of an ink droplet (measured when the distance between the nozzle 18 and the landing position is about 2 mm) is plotted on an ordinate.
  • the deflected ejection of ink droplets was carried out by superimposing the deflection current thorough one piece of the heating element 13, where the principal current of the heating element 13 was 80 mA.
  • the ejecting angle of ink droplets becomes not normal, so that the ejection angle ⁇ x of the ink droplets is increased with increasing bubble-generating time difference.
  • two divided heating elements 13 are provided, and by changing a current passing through each of the heating resistors 13, the two heating resistors 13 are controlled for producing a time difference in the bubble generating time so as to change the ejection of ink droplets in a plurality of directions.
  • the bubble-generating time difference is produced between the two pieces of the heating element 13, the ejecting angle of ink droplets deviates from the normal, so that the landing position of the ink droplets is deflected from their original position.
  • the bubble-generating time can be matched with each other so as to make the ejecting angle of ink droplets normal.
  • Fig. 5 is a drawing for illustrating the deflection in the ejecting direction of ink droplets.
  • a ink droplet i when an ink droplet i is ejected normally to an ink-ejecting face of the ink droplet i (surface of photographic paper), the ink droplet i is ejected without deflection as the arrow shown by doted line in Fig. 5 .
  • the reason to maintain the distance H substantially constant is that when the distance H changes, the landing position of the ink droplets i also changes. That is, when the ink droplets i are ejected from the nozzle 18 normally to the surface of the photographic paper P, even if the distance H changes to some extent, the landing position of the ink droplets i does not change. Whereas, when ink droplets i are ejected with deflection as described above, the landing position of the ink droplets i changes differently with changes in the distance H.
  • the line head 10 in a first mode includes the auxiliary control execution determining means in addition to the principal control means and the auxiliary control means.
  • each liquid ejection part has one ejecting direction by the principal control means and four ejecting directions by the auxiliary control means, five ejecting directions in total.
  • ink droplets are ejected from the entire heads 11 using only the principal control means so as print a test pattern, for example, and the printed result is read by an image reading device, such as an image scanner. Then, from the read result, the presence of the head 11 having the landing positional displacement relative to other heads 11 more than a predetermined value is detected. If the head 11 with the landing positional displacement relative to other heads 11 more than the predetermined value is detected, the displacement is further detected to have what extent displacement, and the head 11 is controlled to change the ejecting direction of ink droplets using the auxiliary control means.
  • Fig. 6 shows an example in that among the heads 11, the Nth head 11 is arranged closer to the (N-1)th head 11, so that the space between the Nth head 11 and the (N-1)th head 11 is reduced (the space between the Nth head 11 and the (N+1)th head 11 is thereby increased).
  • the principal control means is only used for the (N-1)th head 11 and the (N+1)th head 11 so as to select the central ejecting direction among the five ejecting directions.
  • the auxiliary control means is used in addition to the principal control means so as to eject ink droplets.
  • the example in Fig. 6 shows that ink droplets are ejected in the second ejecting direction from the right in the drawing.
  • the principal control means is used so as to eject ink droplets.
  • the landing position is adjusted to agree with that of the head 11 manufactured as designed.
  • Fig. 7 is a drawing of an example in that the landing position of ink droplets is corrected by the principal control means, the auxiliary control means, and the auxiliary control execution determining means in the same way as in Fig. 6 .
  • Fig. 7 although the arrangement space between the heads 11 is constant differently from that in Fig. 6 , an example is shown in that the ejecting direction of the Nth head 11 is different from other heads 11 due to the dispersion in ejection characteristics for each head 11. The example in Fig. 7 shows that the ejecting direction of the Nth head 11 is deflected in the left.
  • ink droplets are ejected for the entire heads 11, while from the (N-1)th head 11 and the (N+1)th head 11, ink droplets are ejected in a substantially normal direction to the surface of the photographic paper P, from the Nth head 11, ink droplets are ejected in a direction deflected in the left.
  • the head 11 in a second mode includes reference-direction setting means in addition to the ejecting-direction changing means described above.
  • the reference-direction setting means is for individually setting for each head 11 one reference principal direction among a plurality of ejecting directions of ink droplets due to the ejecting-direction changing means.
  • each head 11 is also formed to be able to eject ink droplets in five different directions as shown in Fig. 6 , for example.
  • the reference-direction setting means first sets up the central ejecting direction among the five ejecting directions as the principal direction.
  • the Nth head 11 have the landing positional displacement more than a predetermined value.
  • the landing positional displacement can be adjusted. This is the same as in Fig. 7 .
  • the principal direction is set at a direction closest to the normal direction to the photographic paper P; however, it is not necessarily to be set in such a manner.
  • the central ejecting direction is set at the principal direction among the five ejecting directions as the principal direction of the Nth head 11.
  • the second ejecting direction from the left is set at the principal direction.
  • the principal direction of the head 11 is not set at a direction closest to the normal direction to the photographic paper P; however, there is no problem.
  • the head 11 in a third mode includes ejecting-angle setting means in addition to the ejecting-direction changing means described above.
  • Fig. 8 shows an example in that among the heads 11, the Nth head 11 is arranged closer to the (N-1)th head 11, so that the space between the Nth head 11 and the (N-1)th head 11 is reduced (the space between the Nth head 11 and the (N+1)th head 11 is thereby increased).
  • Fig. 9 shows another example in that the landing position of ink droplets is corrected by the ejecting-direction changing means and the ejecting-angle setting means.
  • the angle defined by the left-most ejecting direction in the drawing and the right-most ejecting direction is set at an angle ⁇ .
  • the ejecting angle of the (N-1)th head 11 be the angle ⁇ as designed
  • the ejecting angle of the Nth head 11 be the angle ⁇ ( ⁇ ⁇ )
  • the ejecting angle of the (N+1)th head 11 be the angle ⁇ (> ⁇ ).
  • the Nth head 11 is set to increase the maximum ejecting angle (from the angle ⁇ to the angle ⁇ ). Similarly, the (N+1)th head 11 is set to reduce the maximum ejecting angle (from the angle ⁇ to the angle ⁇ ).
  • the entire heads 11 including the Nth head 11 and the (N+1)th head 11 can be set to have the maximum ejecting angle ⁇ .
  • the landing position can be corrected to the range in that it cannot be corrected otherwise than with changing the ejecting angle.
  • one reference principal direction is individually set by the reference-direction setting means among a plurality of ejecting directions of ink droplets.
  • each head 11 is set at able to eject ink droplets in a plurality of ejecting directions.
  • the angle defined by the left-most ejection direction and the right-most ejecting direction is assumed at the angle ⁇ in the same way as the above.
  • the landing positional displacement can be corrected.
  • the first ejection control means is the means that at least part of the liquid ejection part, using the ejecting-direction changing means, controls liquid-droplet ejection so as to form one pixel line or one pixel using at least two different liquid ejection parts arranged in the vicinity by means of ejecting ink droplets in different directions from at least two different liquid ejection parts arranged in the vicinity so as to land ink droplets on the same pixel line or by means of landing ink droplets on the same pixel region so as to form a pixel.
  • the first ejection control means in a first mode makes the ejection direction of ink droplets ejected from each nozzle 18 variable in 2 J different even-numbered directions with a J-bit control signal (J: positive integer), while sets up the space between the two landing positions of ink droplets being remotest from each other among 2 J directions to be about (2 J - 1) times that between the two nozzles 18 adjacent to each other. Then, when ink droplets are ejected from the nozzle 18, any one of the 2 J directions is selected.
  • J-bit control signal J: positive integer
  • the first ejection control means in a second mode makes the ejection direction of ink droplets ejected from each nozzle 18 variable in (2 J + 1) different odd-numbered directions with a (J + 1)-bit control signal (J: positive integer), while sets up the space between the two landing positions of ink droplets being remotest from each other among (2 J + 1) directions to be about 2 J times that between the two nozzles 18 adjacent to each other. Then, when ink droplets are ejected from the nozzle 18, any one of the (2 J + 1) directions is selected.
  • the deflection angle ⁇ ° is:
  • the ejection directions of ink droplets can be set in a bilateral symmetry in the arranging direction of the nozzles 18.
  • the landing positions of ink droplets are located between the nozzles 18.
  • the ejection directions of ink droplets from the nozzles 18 can be set to have odd-numbered directions. That is, while in the first mode, the ejection directions of ink droplets can be set to have bilateral symmetric even-numbered directions in the arranging direction of the nozzles 18, further using a + one-bit control signal, ink droplets can be ejected just underneath from the nozzles 18.
  • the ejection can be set to have odd-numbered directions.
  • the control signal has two bits so that the ejection has three (2 J + 1) different odd-numbered directions.
  • the space between two landing positions being remotest from each other is set up to be about two-fold (2 J ) that (X in Fig. 12 ) between two nozzles 18 being adjacent to each other (2 J ⁇ X, in Fig. 12 ), and when ink droplets are ejected, any one of three (2 J + 1) ejection directions is selected.
  • ink droplets can also be landed on a pixel region (N-1) and a pixel region (N+1) positioned on both sides of the pixel region N.
  • each liquid ejection part can eject ink droplets at positions of ⁇ (1/2 ⁇ X) ⁇ P(P: positive integer) about the center of its own liquid ejection part in the arranging direction of liquid ejection parts.
  • Fig. 13 shows the procedure forming each pixel on photographic paper by a liquid ejection part with ejection execution signals fed in parallel to the head 11.
  • the ejection execution signal corresponds to an image signal.
  • the number of gray scales of the ejection execution signal of a pixel N is 3; the number of gray scales of the ejection execution signal of a pixel (N+1) is 1; and the number of gray scales of the ejection execution signal of a pixel (N+2) is 2.
  • the ejection signal of each pixel is fed to a predetermined liquid ejection part at cycles a and b while from each liquid ejection part, ink droplets are ejected at the cycles a and b.
  • the cycles a and b correspond to time slots a and b.
  • a plurality of dots, which correspond to the number of gray scales of the ejection execution signal, are formed within one pixel region at cycles a and b.
  • the ejection signal of the pixel N is fed to the liquid ejection part (N-1) and the ejection signal of the pixel (N+2) is fed to the liquid ejection part (N+1).
  • ink droplets are ejected with deflection in a direction a so as to land at the position of the pixel N on the photographic paper.
  • ink droplets are ejected with deflection in the direction a so as to land at the position of the pixel (N+2) on the photographic paper.
  • the ink droplets corresponding to the number of gray scales 2 are thereby landed at each pixel position on the photographic paper at the time slot a. Since the number of gray scales of the ejection execution signal of the pixel (N+2) is 2, the pixel (N+2) is thereby formed. A similar procedure is repeated by the time slot b.
  • the pixel N is composed of the number (two), corresponding to the number of gray scales 3, of dots.
  • ink droplets are not landed continuously (twice in a row) from the same liquid ejection part for forming a pixel, so that dispersion for every liquid ejection parts can be made inconspicuous. Also, if the ejection amount of ink droplets from any one of liquid ejection parts is insufficient, for example, dispersion in an occupied area with dots of each pixel can be reduced.
  • the liquid ejection part used for forming the pixel in the Mth pixel line or used for ejecting first ink droplets for forming the pixel in the Mth pixel line be different from the liquid ejection part used for forming the pixel in the (M+1)th pixel line or used for ejecting first ink droplets for forming the pixel in the (M+1)th pixel line.
  • pixels (dots) formed by the same liquid ejection part cannot be aligned along the same line.
  • the liquid ejection parts used for ejecting first ink droplets for forming the pixel cannot be always identical along the same line.
  • a liquid ejection part may also be selected at random. Also, it may be preferable that the liquid ejection part used for forming the pixel in the Mth pixel line or used for ejecting first ink droplets for forming the pixel in the Mth pixel line be always different from the liquid ejection part used for forming the pixel in the (M+1)th pixel line or used for ejecting first ink droplets for forming the pixel in the (M+1)th pixel line.
  • the ink-droplet ejection can be controlled so as to form one pixel line or one pixel using at least two different liquid ejection parts located in the vicinity in the same way as in the first mode using the first ejection control means.
  • the following ejection control of ink droplets is carried out by second ejection control means.
  • the second ejection control means is ink-droplet ejection control means in that when ink droplets are landed on a pixel region, for every ink-droplet ejection from a liquid ejection part, any one of M different landing positions (M: integers of 2 or more), at least part of which is included within the pixel region, is determined as a landing position (precisely, target landing position) of ink droplets in the arranging direction of liquid ejection parts in the pixel region so that the ejection is controlled so as to land the ink droplets at the determined position.
  • M integers of 2 or more
  • the second ejection control means determines any one of M different landing positions at random (irregularly or without regularity).
  • determining methods at random there is a method for determining any one of M different landing positions using a random number generator, example.
  • the M landing positions are allotted at the space that is about 1/M of the arranging pitch of liquid ejection parts (the nozzles 18).
  • Fig. 15 is a plan view of a state in that ink droplets are landed at any one of the M different landing positions on one pixel region, comparatively showing conventional landing states (left in the drawing) and the landing states according to the embodiment (right in the drawing).
  • square regions surrounded by broken lines are pixel regions. Also circular regions are landed ink droplets (dots).
  • ink droplets are landed at any one of the M different landing positions in the arranging direction of the nozzles 18.
  • a state is shown in that ink droplets are landed at one determined position among M (8) landing positions on one pixel region (7 different landing positions are substantially shown because one of 8 positions corresponds to no landing) (in the drawing, circles shown by solid lines denote the position where ink droplets are landed in practice while circles shown by broken lines denote other landing positions).
  • the ejection command is 1
  • the second position from the left in the drawing is determined, and a state that ink droplets are landed at the determined position is shown.
  • the way when the ejection command is 3 is the same as that when the ejection command is 2 described above.
  • three droplets are landed with no displacement in a lateral direction.
  • third ink droplets are also landed at the position determined regardless of the first and the second landing position.
  • each ink droplet (dot) is arranged at random, and hence the arrangement is microscopically non-uniform, but is rather uniform and isotropic macroscopically, so that the dispersion would not be noticed.
  • this configuration has an effect for masking the ink-droplet dispersion in characteristics of liquid ejection parts. If dots are not randomly arranged, the entire dots are arranged in a regular pattern, so that a portion disturbing the regularity is noticeable. In tittle in particular, color shading is expressed by an area ratio of a dot and a base (portion not covered with a dot); with increasing regularity of the leaving manner of the base, the dispersion becomes noticeable.
  • ink droplets when a plurality of ink droplets (dots) are overlaid so as to form a pixel, for preventing a moiré effect, landing positional accuracies are required more than those in a single color.
  • ink droplets when ink droplets are arranged at random, the moiré problem is not produced, resulting in a simple color dispersion. Accordingly, image degradation due to the moiré can be prevented.
  • the moiré is not a problem in particular; however, the moiré is a problem in a line system. Then, when a method for landing ink droplets at random as in the embodiment is employed, the moiré is difficult to be generated, enabling the line-system ink-jet printer to be easily achieved.
  • landing ink droplets at random extends the landing range of the ink droplets even the total amount of ink landed on photographic paper is the same, so that the drying time of the landed ink droplets can be reduced. Since the printing speed is larger (printing time is shorter) than that of the serial system especially in the line system, its effect is remarkable.
  • the resolution is controlled to increase by number of pixels increasing means.
  • the number of pixels increasing means is the means in that using the above-mentioned ejecting-direction changing means, ink droplets ejected from each liquid ejection part are controlled so as to land at two or more different positions in the arranging direction of liquid ejection parts, so that the number of pixels is increased more than that formed by landing ink droplets from each liquid ejection part at one position.
  • the physical resolution (in construction) of the head 11 is 600 DPI.
  • Fig. 19 herein shows an example in that the Nth head 11 is arranged close to the (N-1)th head 11;
  • Fig. 20 shows an example in that the Nth head 11 has the ejection direction coming near the (N-1)th head 11.
  • Figs. 21 and 22 are drawings showing an example of the combination item (3) in that the first ejection control means and the second ejection control means are provided in addition to the ejecting-direction changing means and the reference-direction setting means. That is, in Figs. 21 and 22 , landing positions are assigned at random within the same pixel region in addition to the examples of Figs. 19 and 20 , respectively.
  • ink droplets are landed on the pixel line located just underneath (principal direction), in addition to the central ejection direction (the seventh direction from the left, the principal direction), the sixth or eighth ejection direction from the left is selected at random.
  • the second or the forth ejection direction from the left is selected at random.
  • the second or the fourth ejection direction from the right is selected at random.
  • the ejecting-angle setting means of the heads 11 other than the Nth head 11 controls ink droplets to be ejected without changing the ejecting angle.
  • the ejecting-angle setting means of the Nth head 11 establishes ejecting angles so that ink droplets are ejected in arrow directions shown by heavy lines in the drawings by shifting ejecting angles of ink droplets together on the right by a predetermined angle.
  • Figs. 24A and 24B are drawings showing an example of the combination item (6) in that the second ejection control means and the number of pixels increasing means are provided in addition to the ejecting-direction changing means and the reference-direction setting means.
  • Fig. 24A shows an example in that the Nth head 11 is arranged close to the (N-1) th head 11;
  • Fig. 24B shows an example in that the Nth head 11 has the ejection direction coming near the (N-1)th head 11.
  • Fig. 24A for example, of Figs. 24A and 24B , by the ejecting-direction changing means, while from each liquid ejection part of each head 11, ink droplets can be ejected in a plurality of different directions (13 directions in this example), one ejection direction is established for each head 11 as a reference principal direction.
  • the central ejection direction (the seventh direction from the left) is established as the principal direction.
  • the second ejection control means in addition to the principal direction, any one of three ejection directions including the sixth and the eighth ejection direction from the left is selected at random.
  • the number of pixels increasing means when ink droplets are landed on the left pixel line adjacent thereto, in addition to the third ejection direction from the left, any one of three ejection directions including the second or the fourth ejection direction from the left is selected at random. Similarly, when ink droplets are landed on the right adjacent pixel line, in addition to the third ejection direction from the right, any one of three ejection directions including the second or the fourth ejection direction from the right is selected at random. In such a manner, by the number of pixels increasing means, while the resolution is increased, for each pixel line, landing positions of ink droplets are randomly assigned within the same pixel line.
  • Figs. 25A and 25B are drawings showing an example of the combination item (5) in that the first ejection control means and the number of pixels increasing means are provided in addition to the ejecting-direction changing means and the reference-direction setting means.
  • Fig. 25A of Figs. 25A and 25B shows an example in that the Nth head 11 is arranged close to the (N-1)th head 11;
  • Fig. 24B shows an example in that the Nth head 11 has the ejection direction coming near the (N-1)th head 11.
  • Figs. 26A and 26B in addition to the example in Figs. 25A and 25B , by the second ejection control means, landing positions of ink droplets are further assigned at random within the same pixel line.
  • any one of three ejection directions including ejection directions during landing of ink droplets in the example of Figs. 25A and 25B and lateral directions on both sides thereof is selected at random.
  • the ejecting-direction changing means controls the ejection direction of ink droplets to be ejected in at least two different directions by changing energy supply to the heating resistor 13.
  • the auxiliary control means controls ink droplets to be ejected in a direction different from that of the ink droplets ejected by the principal control means by supplying energy to the heating resistor 13 in a different way from that of the principal control means.
  • a circuit having a switching element referred to as a current mirror circuit in the following description
  • electric current supplied to each heating resistor 13 is controlled by passing current between the heating resistors 13 or by discharging the current from between the heating resistors 13, so that the ejecting-direction changing means controls the ejection direction of ink droplets to be ejected in at least two different directions, or the auxiliary control means controls the ejection direction of ink droplets to be ejected in a direction different from that by the principal control means.
  • Fig. 27 is a drawing of an ejection-control circuit 50 according to the embodiment.
  • the current mirror circuit (referred to as a CM circuit below) is connected.
  • CM circuit By passing current between the heating resistors 13 or by discharging the current from between the heating resistors 13, the amount of current passing through each heating resistor 13 is differentiated, thereby changing the ejection direction of ink droplets into a plurality of directions in the arranging direction of the nozzles 18 (liquid ejection parts).
  • a power supply Vh is for applying voltage across the resistors Rh-A and Rh-B.
  • the ejection control circuit 50 includes transistors M1 to M19.
  • numeral ( ⁇ 1) (for the transistors M16 and M19) shows that a standard element is included.
  • numeral (x2) shows that an element equivalent to two standard elements connected in parallel is included.
  • Numeral ( ⁇ N) shows below that an element equivalent to N standard elements connected in parallel is included.
  • Polarity changing switches Dpx and Dpy are switches for determining the ejection direction of ink droplets in any one of the left and the right.
  • first ejection control switches D4, D5, and D6 and second ejection control switches D1, D2, and D3 are switches for determining the deflection when ink droplets are ejected with deflection.
  • the transistors M2 and M4 and the transistors M12 and M13 function as operational amplifiers (switching elements) for the CM circuit, respectively. That is, these transistors M2 and M4, and M12 and M13 are for passing the electric current between the resistors Rh-A and Rh-B or for discharging the current from between the resistors Rh-A and Rh-B via the CM circuit.
  • the transistors M7, M9, and M11 and the transistors M14, M15, and M16 are elements to be a constant current source of the MC circuit, respectively.
  • the respective drains of the transistors M7, M9, and M11 are connected to the sources and the back gates of the transistors M2 and M4.
  • the respective drains of the transistors M14, M15, and M16 are connected to the sources and the back gates of the transistors M12 and M13.
  • the transistor M7 has a capacitance ( ⁇ 8); the transistor M9 has a capacitance ( ⁇ 4); and the transistor M11 has a capacitance ( ⁇ 2).
  • These three transistors M7, M9, and M11 connected together in parallel constitute a current source element group.
  • the transistor M14 has a capacitance ( ⁇ 4); the transistor M15 has a capacitance ( ⁇ 2); and the transistor M16 has a capacitance ( ⁇ 1).
  • the transistors M7, M9, and M11 and the transistors M14, M15, and M16 which are functioning as current source elements, the transistors having the same current capacitance as that of each transistor (the transistors M6, M8, and M10 and the transistors M17, M18, and M19) are connected.
  • the first ejection control switches D6, D5, and D4 and the second ejection control switches D3, D2, and D1 are connected.
  • the transistor M6 when the first ejection control switch D6 is turned on and an appropriate voltage Vx is applied between an amplitude control terminal Z and the ground, for example, the transistor M6 is turned on, so that a current when the voltage Vx is applied passes through the transistor M7.
  • the first ejection control switches D6, D5, and D4 and the second ejection control switches D3, D2, and D1 are controlled to turn on/off, and hence the transistors M6 to M11 and the transistors M14 to M19 can be controlled to turn on/off.
  • the ratio of the transistors M7, M9, and M11 is ( ⁇ 8), ( ⁇ 4), and ( ⁇ 2)
  • the ratio of the respective drain currents Id is 8:4:2.
  • the ratio of the transistors M14, M15, and M16 is ( ⁇ 4), ( ⁇ 2), and ( ⁇ 1)
  • the ratio of the respective drain currents Id is 4:2:1.
  • the transistor M6, M8, or M10 which corresponds to the turned-on first ejection control switch, is turned on, and any one of the transistor M7, M9, and M11, which is connected to the former transistor, is further turned on.
  • the current flowing through the resistor Rh-A branches toward the transistor M2 and the resistor Rh-B so as to discharge into the transistor M2. Then, the current flowing through the transistor M2 is fed to the ground via the transistors M7 and M6.
  • the transistor M4 is required to be on for the current to flow through the transistor M5.
  • the control turning on/off the first ejection control switches D6 to D4 enables the amount of current discharged from the transistors M2 and M4 to be changed. That is, the control turning on/off the first ejection control switches D6 to D4 enables the current flowing through the resistors Rh-A and Rh-B to be changed.
  • the deflection for each step can be changed while the rate of the drain currents flowing through the transistors M7, M6, M9, M8, M11, and M10 remains as it is 8:4:2.
  • Figs. 28A and 28B are tables showing states of the polarity changing switch Dpx and the first ejection control switches D6 to D4, and changes in landing positions of dots (ink droplets) in the arranging direction of the nozzles 18.
  • the second ejection control switches D3, D2, and D1 correspond to the first ejection control switches D6, D5, and D4, respectively.
  • the transistors M12 and M13 connected to the second ejection control switches D1 to D3 correspond to the transistors M2 and M4 on the side of the first ejection control switches D4 to D6, respectively.
  • the polarity changing switch Dpy further corresponds to the polarity changing switch Dpx.
  • the transistors M14 to M19 functioning as current source elements also corresponds to the transistors M6 to M11, respectively.
  • the capacity of the transistor M14 functioning as a current source element is different from that on the side of the first ejection control switches D4 to D6.
  • the transistor M14 functioning as a current source element on the side of the second ejection control switches D1 to D3 is set to have a half capacity of the transistor M6 functioning as a current source element on the side of the first ejection control switches D4 to D6. Others are the same.
  • the second ejection control switches D1 to D3 and the polarity changing switch Dpy are mainly used in executing the second ejection control means. Therefore, the control way as shown in Fig. 28B of Figs. 28A and 28B may be rational.
  • the polarity changing switch Dpx corresponds to the polarity changing switch Dpy;
  • the first ejection control switches D6, D5, and D4 correspond to the second ejection control switches D3, D2, and D1, respectively.
  • the amplitude control terminal Z on the side of the first ejection control switches D4 to D6 is identical to that on the side of the second ejection control switches D1 to D3.
  • the voltage Vx applied to the amplitude control terminal Z is established in view of the control amount by the second ejection control switches D1 to D3, for example, the landing positions of ink droplets by the control of the first ejection control switches D4 to D6 are also determined on the basis of the voltage Vx.
  • the ejection control is established to have a predetermined relationship between the ejection control of ink droplets on the side of the first ejection control switches D4 to D6 and that on the side of the second ejection control switches D1 to D3.
  • the ejection control of ink droplets (the space between the landing positions of ink droplets) is determined on any one side, based on the determined results, the ejection control of ink droplets (the space between the landing positions of ink droplets) is determined on the other side.
  • the amplitude control terminal Z on the side of the first ejection control switches D4 to D6 may also be provided separately from that on the side of the second ejection control switches D1 to D3.
  • the ejection direction of ink droplets (the landing position of ink droplets) can be established at more multi-steps.
  • the ejection control circuit 50 shown in Fig. 27 is provided for each liquid ejection part; however, the above-mentioned control is performed for each head 11.
  • the switches of the ejection control circuit 50 are provided in one for each head 11. By turning the switches on/off in units of the head 11, the entire liquid ejection parts within the head 11 are turned on/off simultaneously. For example, in one head 11, by turning on/off one first ejection control switch D6, the first ejection control switches D6 of the entire liquid ejection parts of the head 11 are simultaneously turned on/off.
  • the ejecting-direction changing means or the principal control means and the auxiliary control means can be executed.
  • the auxiliary control execution determining means may store whether the auxiliary control means is executed for every heads 11 or not in a memory together with the on/off state of each switch when the means is executed.
  • the reference-direction setting means is executed together with the ejecting-direction changing means, i.e., when a reference principal direction is established for each head 11, the on/off state of each switch may be stored in units of the head 11 in the same way.
  • the deflection (ejecting angle) per one step can be changed.
  • the ejecting-angle setting means by adjusting the voltage Vx applied to the amplitude control terminal Z so as to establish a desired ejecting angle for each head 11, the voltage Vx at this time may be stored in a memory.
  • the first ejection control means can be executed by controlling the first ejection control switches D4 to D6 to be turned on/off. Furthermore, the second ejection control means can be executed by controlling the second ejection control switches D1 to D3 to be turned on/off.
  • the first ejection control switches D4 to D6 can also be used to make them serve a double purpose.
  • the first ejection control switches D4 to D6 are used as well as the number of pixels increasing means, it is preferable that the first ejection control switches D4 to D6 be changed to 0 or 1 so that the ejection direction be changed to 15 stages. That is, this is because the number of ejection directions capable of covering a plurality of ejection directions by the number of pixels increasing means and a plurality of ejection directions by the first ejection control means is required.
  • first ejection control switches D4 to D6 are arranged in parallel with the second ejection control switches D1 to D3 so that the ejection control switches, the polarity changing switches, and the transistors for the number of pixels increasing means may be obviously provided separately.
  • the energy-generating element of an electrostatic ejection system includes a resonant panel and two electrodes disposed underneath the resonant panel with an air space therebetween.
  • the resonant panel is deflected downward by applying a voltage between both the electrodes, and then, the voltage is turned to 0 V so as to release an electrostatic force. Utilizing an elastic force produced when the resonant panel is returned to the original state, ink droplets are ejected.
  • a time difference may be produced between two energy-generating elements, or the voltage may be changed for two energy-generating elements, for example.
  • the energy-generating element of a piezoelectric system is made of a composite composed of a piezoelectric element having electrodes disposed on both sides and a resonant panel.
  • a voltage is applied to the electrodes on both sides of the piezoelectric element, a bending moment is produced in the resonant panel by a piezoelectric effect so as to deflect the resonant panel.
  • ink droplets are ejected.
  • stripe non-uniformity can be made in inconspicuous states by correcting the ejection direction of the unit head. Thereby, printing quality can be improved.

Landscapes

  • Physics & Mathematics (AREA)
  • Geometry (AREA)
  • Particle Formation And Scattering Control In Inkjet Printers (AREA)
  • Ink Jet (AREA)

Abstract

単位ヘッド間でインク液滴の吐出特性のばらつきがある場合や、単位ヘッドの配置精度にばらつきがある場合であっても、各単位ヘッドに応じた補正を行うことで、スジムラの軽減等を図る。液体吐出部を配列した（単位）ヘッド（１１）を、ヘッド（１１）間で繋がるように複数並設したラインヘッド（１０）を備える液体吐出装置であって、各液体吐出部のノズルから吐出する液滴の吐出方向を、液体吐出部の配列方向において複数の方向に可変とした吐出方向可変手段と、各ヘッド（１１）ごとに、吐出方向可変手段による液滴の複数の吐出方向のうち、基準となる１つの主方向を個別に設定する基準方向設定手段とを備える。「Ｎ−１」番目及び「Ｎ＋１」番目のヘッド１１では、左から３番目の吐出方向が主方向に設定されており、「Ｎ」番目のヘッド（１１）では右から２番目の吐出方向が主方向に設定されている。
EP04746236A 2003-06-16 2004-06-16 Liquid jet device and liquid jet method Expired - Lifetime EP1634706B1 (en)

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JP2003170269A JP2005001346A (ja) 2003-06-16 2003-06-16 液体吐出装置及び液体吐出方法
PCT/JP2004/008767 WO2004110766A1 (ja) 2003-06-16 2004-06-16 液体吐出装置及び液体吐出方法

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Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4632648B2 (ja) 2003-10-02 2011-02-16 ソニー株式会社 液体吐出装置及び液体吐出方法
JP4852471B2 (ja) 2007-05-01 2012-01-11 株式会社Ｔｒｉｎｃ Ｄｂｄプラズマ式除電器
JP2007261217A (ja) * 2006-03-29 2007-10-11 Sony Corp 印刷装置、パターンテーブル最適化装置及びコンピュータプログラム
US8210638B2 (en) * 2007-02-14 2012-07-03 Canon Kabushiki Kaisha Ink jet printing apparatus and ink jet priting method
WO2009070136A1 (en) * 2007-11-29 2009-06-04 Hewlett-Packard Development Company, L.P. Printing
JP2013180512A (ja) * 2012-03-02 2013-09-12 Canon Inc インクジェット記録ヘッド、およびインクジェット記録方法
JP6999674B2 (ja) 2016-12-22 2022-01-18 ベーリンゲ、イノベイション、アクチボラグ タングをパネルの挿入溝に挿入するための装置
CN107128069B (zh) * 2017-04-28 2019-07-02 京东方科技集团股份有限公司 调节喷墨打印装置的方法、喷墨打印方法、装置及其系统
DE102018101295B4 (de) * 2018-01-22 2020-10-08 Canon Production Printing Holding B.V. Verfahren und Vorrichtung zum Bedrucken eines Aufzeichnungsträgers mit einem Beschichtungsstoff und entsprechendes Drucksystem

Family Cites Families (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH03227632A (ja) * 1990-02-02 1991-10-08 Canon Inc インクジェット記録ヘッドの駆動方法及び記録装置
ATE122967T1 (de) 1990-02-02 1995-06-15 Canon Kk Tintenstrahlaufzeichnungskopf und tintenstrahlaufzeichnungsgerät mit diesem aufzeichnungskopf.
JPH09286107A (ja) * 1996-04-22 1997-11-04 Canon Inc インクジェットプリントヘッドの基体、インクジェットプリントヘッド、およびインクジェットプリント装置
JP2001105584A (ja) * 1999-10-14 2001-04-17 Canon Inc インクジェット記録装置
JP2001150657A (ja) * 1999-11-29 2001-06-05 Canon Inc 記録装置および記録方法
WO2001042016A1 (fr) * 1999-12-06 2001-06-14 Fujitsu Limited Imprimante a jet d'encre
JP4250354B2 (ja) 2000-07-21 2009-04-08 富士フイルム株式会社 記録ヘッド
JP4617544B2 (ja) 2000-07-25 2011-01-26 ソニー株式会社 プリンタ及びプリンタヘッド
JP2002192727A (ja) 2000-12-27 2002-07-10 Canon Inc インクジェット記録ヘッド、インクジェット記録装置およびインクジェット記録方法
JP2002240287A (ja) * 2001-02-20 2002-08-28 Sony Corp プリンタヘッド、プリンタ及びプリンタヘッドの駆動方法
JP2002254649A (ja) 2001-03-06 2002-09-11 Sony Corp プリンタヘッド、プリンタ及びプリンタヘッドの駆動方法
JP2003136728A (ja) 2001-11-05 2003-05-14 Sony Corp インクジェットプリントヘッド及びこれを備えたインクジェットプリンタ、並びにインクジェットプリントヘッドの製造方法
JP2002036552A (ja) 2001-07-24 2002-02-05 Ricoh Co Ltd 液体噴射記録装置
JP2003080696A (ja) * 2001-09-10 2003-03-19 Sony Corp プリンタヘッドチップ及びプリンタヘッド
JP3617644B2 (ja) * 2002-03-26 2005-02-09 ソニー株式会社 液体吐出装置
JP2004001364A (ja) * 2002-04-16 2004-01-08 Sony Corp 液体吐出装置及び液体吐出方法
JP4023331B2 (ja) * 2002-06-03 2007-12-19 ソニー株式会社 液体吐出装置及び液体吐出方法
JP3741214B2 (ja) * 2002-11-18 2006-02-01 ソニー株式会社 液体吐出装置
EP1391303B1 (en) * 2002-08-20 2009-02-18 Sony Corporation Liquid ejecting device and liquid ejecting method

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JP2005001346A (ja) 2005-01-06
US20080068415A1 (en) 2008-03-20
CN1700988A (zh) 2005-11-23
KR101162369B1 (ko) 2012-07-04
WO2004110766A1 (ja) 2004-12-23
US20080068414A1 (en) 2008-03-20
US20080074452A1 (en) 2008-03-27
EP1634706A4 (en) 2010-03-31
KR20060030846A (ko) 2006-04-11
US7823998B2 (en) 2010-11-02
US20060055714A1 (en) 2006-03-16
CN100415520C (zh) 2008-09-03
EP1634706A1 (en) 2006-03-15

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